NVIDIA GeForce GTX 860M SLI
The NVIDIA GeForce GTX 860M SLI is a high-end DirectX 12-compatible graphics solution for laptops, consisting of two GeForce GTX 860M. Each card has a 28 nm GM107 core based on the Maxwell architecture. The clocks for the SLI-setup are identical to a single GTX 860M. With SLI, each card usually renders a single frame (AFR mode). Therefore, it may suffer from micro stuttering in low fps ranges of 30fps. This happens because of different timespans between two frames (e.g., irregular delays between sequential frames).
Alternatively, there is also a version based on the Kepler chip GK104, which has 1152 shader units clocked at 797 MHz.
Compared to Kepler, Maxwell has been optimized in several details to increase power efficiency. Smaller Streaming Multiprocessors (SMM) with only 128 ALUs (Kepler: 192) and an optimized scheduler should lead to better utilization of the shaders. Nvidia promises that a Maxwell SMM with 128 ALUs can offer 90 percent of the performance of a Kepler SMX with 192 ALUs. Each of the two GM107 features 5 SMMs and thus 640 shader cores, 40 TMUs and 16 ROPs (128-bit interface).
Another optimization is the massively enlarged L2 cache (GM107: 2 MB). The increased size can handle some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing the performance.
Similar to Fermi and Kepler, Maxwell / GM107 supports DirectX 12 with feature level 11.0 only.
The GeForce GTX 860M SLI is about 70 - 80 percent faster than a single GTX 860M, leading to a performance somewhere between a single GeForce GTX 680 (desktop) and Radeon R9 280X (desktop). Accordingly, the 860M SLI competes with the high-end single-GPU GeForce GTX 880M. Most games (as of 2014) are playable at the highest detail setting and in FullHD resolution. In many cases it is even possible to activate additional anti-aliasing.
GM107 integrates the sixth generation of the PureVideo HD video engine (VP6), offering a better decoding performance for H.264 and MPEG-2 videos. Of course, VP6 supports all features of previous generations (4K support, PIP, video encoding via NVENC API). Unfortunately, HDMI 2.0 is still not supported.
The power consumption of the GeForce GTX 860M SLI should double from 60 to about 120 watts (including board and memory) compared to a single GTX 860M. Therefore, only large desktop replacements can handle the heat.
|GeForce GTX 800M Series|
|Pipelines||1280 - unified|
|Core Speed||1029 MHz|
|Memory Speed||5000 MHz|
|Memory Bus Width||2x 128 Bit|
|Max. Amount of Memory||2x 4096 MB|
|DirectX||DirectX 12 (FL 11_0), Shader 5.0|
|Transistor Count||2x 1870 Million|
|Features||Battery Boost, GameStream, ShadowPlay, GPU Boost 2.0, Optimus, PhysX, CUDA, SLI, GeForce Experience|
|Date of Announcement||12.03.2014|